修正讲解音频时长显示

- 未加载媒体元数据时默认显示零时长
- 使用音频文件真实媒体时长更新播放器
- 避免使用不准确的接口时长覆盖播放器显示
- 补充音频时长回归测试

Made-with: Proma

src/pages/exhibit/detail.vue

@@ -374,14 +374,9 @@ const formatDetailAudioTime = (seconds?: number) => {
 
   return `${minutes}:${remainSeconds.toString().padStart(2, '0')}`
 }
-const detailAudioDurationSeconds = computed(() => {
-  if (!isCurrentDetailAudioTarget.value) return exhibit.value.audio.duration || 0
-
-  return globalAudioPlayer.duration.value
-    || globalAudioPlayer.currentAudio.value?.duration
-    || exhibit.value.audio.duration
-    || 0
-})
+const detailAudioDurationSeconds = computed(() => (
+  isCurrentDetailAudioTarget.value ? globalAudioPlayer.duration.value : 0
+))
 const detailAudioCurrentSeconds = computed(() => (
   isCurrentDetailAudioTarget.value ? globalAudioPlayer.currentTime.value : 0
 ))